Effect of rosemary extracts on the stabilization of frying oil during deepfat frying

Rapeseed oil and a mixture of rapeseed oil with palmolein containing silico ne oil were used for preparation of french fries. The intermittent frying w as continued for 5 days in a household fryer with replenishment of used oil , The decomposition of polyunsaturated triacylglycerols, formation of polar substances, polymers, colored products and conjugated dienes, but also of several sensory attributes, correlated with frying time. Polymers, dienes a nd coloration were closely intercorrelated and correlated with sensory char acteristics of oil and fries, particularly when multiple regression was app lied for prediction. Rosemary extracts inhibited the formation of polar sub stances, polymers and decomposition of polyunsaturated triacylglycerols, es pecially in the case of rapeseed oil and improved the sensory attributes of french fries.